Why is time slower in rockets?
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- čas přidán 14. 06. 2024
- The third in our gamma trilogy - this time Professor Mike Merrifield goes into the mathematics!
Gamma: • Time Dilation - Sixty ...
Gamma Reloaded: • Relativity Paradox - S...
Animations by Drew Mokris.
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This project features scientists from The University of Nottingham
www.nottingham.ac.uk/physics/i...
Sixty Symbols videos by Brady Haran
A run-down of Brady's channels:
periodicvideos.blogspot.co.uk/... - Věda a technologie
I love how beautifully simple the math is for something so hard to comprehend or achieve.
Einstein did too. Many physicists and mathematicians do, actually, and you could say it's the fundamental motivation behind those fields: to describe all the events in our universe as "laws" or "patterns" with the language of math. It's also kind of why Einstein hated the probabilistic nature of quantum mechanics... it _feels_ as if the mechanics aren't fully described if our theories _must_ involve something as inelegant as probabilities.
Such elegance is also a goal of String Theory: that everything in the universe can be boiled down to a handful of different kinds of strings and how they vibrate. Of course, the explanation of how to get from those simple building blocks up to what we experience in our daily lives gets _absurdly_ complex since it's essentially _the_ emergent system of the universe... but nonetheless, all that complexity occurs as a consequence of relatively simple building blocks. At least, so the theory goes.
I was thinking the same thing. Very elegant way of illustrating such a complex topic.
Well.. Have you ever tried general relativity ? :D
I don't understand, what is so hard to understand here?
Yyu
whenever i forget how this works i always come back to this video. I haven't found any other explanation clearer and more concise than this. Thank you!
I always teach this to my A-level physics students in the summer term - they're gonna love this!
The animations with the light clock (especially when it's in the moving rocket) are so much better than my crappy powerpoint light clocks!
AlanKey86 Sir, do you teach online? Could I learn from you?
and acceleration just changes the right angle triangle they are traveling on. Therefore it draws a curve that can look like water waves in the direction of motion ( or opposite it in deceleration)
Great animation, Brady. Clear and entertaining as always. Great job!
+MozartJunior22 Animations by Drew Mokris
"Why is time slower in rockets?" This is an easy one. Time slows down, particularly during the holidays, because of relatives. This has been known since Einstein's famous Theory of Relativity which states that time slows by 1 unit for every distant cousin, two units for every drunken uncle and E*(by gum!)² for every in-law from Yorkshire. I thought EVERYBODY knew that. The simple solution is to fly solo.
That was hysterical. Thank you for that, I needed it! :)
Is this supposed to be funny?
+Martin Kunev
Yes, it is. Say "hi" to your Asperger's.
Winston Knowitall HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
colourmegone If only I could hear these words from the mouth of the professor in this video, I would be able to die in peace.
Sixty Symbols never ceases to amaze me. What a great video.
Well, isn't that special!
That's the first explanation of special relativity I've ever seen that actually makes sense to me.
I do find it interesting that from the observer's frame of reference it looks like the light is going to miss the mirror, because it's aimed at where the mirror is at time the light is launched, not where the mirror will be when the light arrives.
The ship would be super compressed in the direction it's moving at the speed of light compared to the observer.
Links to the previous Gamma Videos...
Gamma: czcams.com/video/jlJNsRZ4WxI/video.html
Gamma Reloaded: czcams.com/video/kGsbBw1I0Rg/video.html
I love this video (and many of your others), and I use this one with my high school students, but the one big problem with it is that Prof Merrifield talks very, very fast. It is hard to keep up with him, and even harder for students who might not be native speakers of English.
Andrew M Agreed. Maybe subtitles would help?
***** I don't know. Who do *you* think I am?
+Sixty Symbols Can you please do a follow-up video explaining the twin's paradox in a similar way as this video? It seems the person on the jet would see the clock on the ground having a larger h, thus thinking time on the ground would be slower. The other gamma video explained there was asymmetry here. Where does the asymmetry come from?
Anthony Trupiano I *think* it has to do with who turns around and comes back. That introduces acceleration, which also dilates time. But that's covered in general relativity.
He has the shirt backwards
Nice and simple, thanks prof.
Third in the series... Gamma Revolutions.
I laughed out loud.
Just got the reference :P
35 years I've struggled with this I now understand it perfectly it was so simple best explanation on any topic I have seen. excellent, thank you
What if you rotate the clock 90 degrees
Interesting question. From outside of the rocket, you'll still see the beam of light having to travel a longer distance to get to the mirror (and so it will take a longer time), but a shorter distance to get back to the sensor.
If you rotate the clock 90 degrees it becomes: sqrt(-1)*the clock
I think the stationary observer would see the light become blue-shifted, more so in the direction of movement, less so the other way (but still blue-shifted).
Everything would be the same. Just like if the stationary observer were looking from the front or back side of the plane instead of it's profile. And as someone said, you would just have to measure the blue/red shift instead of with simple geometry.
If you rotate the clock by 90 degrees, yes the light becomes red/blue shifted, but that doesn't change the period of the clock. The light will have to travel more in one direction, but then equally less in the other direction, so the period will be the same. But the distance between the mirror and the emitter/detector will actually be shorter because of lenght contraction, which would mean the clock would actually go faster??? Idk the answer
Loved this video, reminded of the days in AP Physics
Its so cool how you can derive such complicated concepts from the simplest of ideas
Thank you so much.
i always found it hard to understand what it meant by "for this to not be true the speed of light would have to speed up or slow down
Honestly and without exaggeration, this video alone enlightened me more than every other CZcams video/ Documentary I've ever watched on time dilation combined.
For the first time in life, I'm actually convinced about the fact that time isn't a constant. Unlike before when I used to force myself into believing it simply because it was experimentally proven, I can now derive the formula whenever I want thanks to you!
+Mohammed Zaid If you want experimental evidence of time dilation too, look up the 'Hafele-Keating experiment'.
*****
Yes. I knoow about that. When I mentioned "experimentally proven" there, I actually meant to point out at this one. But I didn't remember the name while writing it.
Thanks :)
It's amazing how surprisingly clear things can be explained with math. I don't know why people are reluctant to use it.
@@cesarsosa4617 It's true that math is an incredibly powerful approach to understanding nature. It's a tragedy that so many are adverse to it.
I recommend watching the CZcams video where Leonard Susskind explains why math works. I find the explanation to be supportive of your experience of trying to understand time dilation. You weren’t able to comprehend time dilation, even experimentally, because it’s just not something that we encounter or are familiar with in everyday physics.
I love this Gamma series so much. Thanks so much for making such great content!
Wow, first video I've watched of yours and I watched it all the way through. Very interesting.
I love the simplicity of this!
still blows my mind though
I actually got this first time. Great video.
I love what Sixty Symbols usually does--introducing people to often reasonably complex ideas without amy real math--but I love this new, slightly mathier video. Honestly, I think it would be awesome to see more like this, maybe at a higher level of mathiness--it would give people an insight into both the concepts and a bit if the math behind them, which is absolutely crucial to doing physics. I don't know how one would best do that without either seriously increasing your workload by making those in addition to the normal ones, or making less of the non-math videos (which would be a shame), but it would e a neat idea. I hope to see more stuff like this in the future!
We need more videos like this.
Great video! It would be better if you guys didn't gloss over the algebra at the end. Even if it is very simple, seeing it being done all the way, step by step, would be enlightening to a lot of people.
(ct)² = (vt)² + (cτ)²
c²t² = v²t² + c²τ² (distributing the squares)
c²t² - v²t² = c²τ² (isolating the t's on the same side of the equation by subtracting v²t² from both sides)
t²(c² - v²) = c²τ² (factoring the t² out on the left)
t² = c²τ² / (c² - v²) (dividing everything by (c² - v²))
t² = τ² / (1 - v²/c²) (divide both numerator and denominator by c², so the fraction remains unchanged and you get rid of the c² terms)
t = τ / √(1 - v²/c²) (take the square root of both sides)
he should have at least showed all the steps instead of just putting the final solution
After distributing the squares, divide both sides by c²t² to simplify the illustration -
1 = τ²/t² + v²/c²
1 - v²/c² = τ²/t²
√(1 - v²/c²) = τ/t
And then solve for t or τ easily.
t√(1 - v²/c²) = τ
t = τ/√(1 - v²/c²)
thanks for the steps it really helped me to improve my derivation skills
can someone ID the pen used in this video? it writes beautifully
They are known as stick pens
I'm 2 years late, but: it's an Artline 200. Not sure what writing width, but...that's the pen.
.4 mm
Sixty symbols is by far my favorite youtube channel. Brady, you ask fantastic people fantastic questions. I could watch your videos all day long and some days I pretty much do.
More and more and more ......
I love it when you supplement your vids with the maths. It's the icing on the cake.
Many thanks.
The funny thing is that the time is slower in the observed objects from the perspective of both sides (reference frames). There's something fishy about this.
The thing I was always missing (but time to time I GET it and then forget again) is that person on the ground moves with speed of rocket in rocket's frame of reference. So In this case clock on the group should go slower. But how both clocks can go slower. In the end, when rocket get back someone should have less time on his clock.
Good question. You are implicitly assuming the clocks are to be compared directly. You assume the rocket ship lands on earth to make the comparison. In that case, the rocket's clock will be behind ours. The thing that makes the rocket-man age less is the acceleration that his frame of reference "feels" when it meets up with us in our frame of reference at the end of the journey. If on the other hand, he were to keep moving uniformly and we were to launch ourselves onto his rocket (experiencing lots of G's), we would find that we have aged less than the rocket man. Einstein's general theory gets the right answer. The special theory is not sufficient.
You have to take into a account the effect of acceleration which is not part of STR.
This is the famous "twins paradox". The rocket clock will have less time passed. If the rocket flies straight for some time and then turns back, at the point of turning back its frame of reference will change (as its speed changes), and the plane of simultaneous events will rotate. For them it will look like Earth's clock advanced forward very quickly. For example, sitting on Earth we "see" the rocket flies for 5 years then turns back and flies back 5 years. Its clock is slower however, so it only takes 1 month of rocket time to go there and 1 month back. For the astronauts just 2 months will pass instead of 10 years. At both ways (there and back) they'll see Earth clock ticking slower: on the way there they'll see just the first 12 hours of Earth history, on the way back they'll see the last 12 hours of Earth history. The gap (10 years - 24 hours) will be "jumped" when they turn the rocket back.
That's essentially the twin paradox. The solution comes from the fact that one of them will have to turn around: i.e. decelerate and accelerate again. At that point they are no longer travelling at constant velocity and so you need general relativity to solve it. I think they talk about it in the twin paradox video.
If the rocket gets back, it will have to be subject to an acceleration, and that is the key to the paradox. Although there's no "absolute speed" (so you can imagine a rocket at constant v and a steady group of observers as well as a steady rocket and a moving group of observers), there IS an "absolute acceleration", and this breaks the symmetry of the problem. (And if you do the calculation, it turns out that the one who accelerates to get back is in the end younger).
IMHO ;)
This guy is gold! He explains it so well and understandable. Saw a lot of videos on relativity, but this one makes the concept so much more comprehensible!
This is an awesome vid! Thanks professor. Brady, go easy on the "no maths!" rule in Sixty Symbols. Maths itself is just a bunch of symbols, each representing some property, which we use to show the relations between these properties in a simple way. Nothing to be afraid of.
But what if the guys in the space ship do the same calculation for someone on the ground? Wouldn't the ground-people's clock have to run slower since their light clock would follow the same pattern relative to the space ship? =\
That's why it's called "relativity".
Things are different relative to different points of view.
Yep. Both the earthman and the rocket man will see the other's clock running slower than his own. (And both players will see a red-shift in the light given off by the other.) It all depends on ones point of view. See my response to Aleksandr Motsjonov in these comments.
Yes, that's actually correct! And physicists take this into account when designing things like gps satellites that require equal timing.
I was going to ask the same thing but I suspect, from their point of view, they would observe the same thing. Not sure how this would not introduce some sort of contradiction though...
There was a good lecture related with your question somewhere, which I cannot find now (prolly on ted.com, or online Yale lectures), and maybe there was a vid on some of Brady's channels. The difference is that the guy in the rocket accelerates and he can measure it, while the guy on Earth cannot. I belive prof Mike is not talking about it for the sake of clarity.
Another great video! Congrats! But one question; the light in the moving ship is moving forward? How is it moving forward and not back since the ship is moving itself? I would assume the ship is moving forward and the light shoots up, leaving light behind meaning it would never touch the mirror and reflect back into the light detector. Feedback would be very much appreciated! Thanks!
I'm definitely not an expert on this, but I'd say it's similar to being in a car. Imagine you are moving on the highway at 100km/h, and you toss a tennis ball to someone sitting in across from you. Despite it seeming like the tennis ball should just stop, it continues to move because at the same velocity the person who threw it is moving at, 100km/h. I don't know if light has different physics, but that is the only explanation I can think of.
Hope that helps :)
It's not actually moving forward from the people in the ship's perspective. You have to take into account what was explained in the beginning, that the laws of physics are the same as long as something's moving at a constant speed. The rocket is not accelerating, in which case what you say would be true, but it is moving at a constant speed.. Say you're in a plane moving at constant speed and you throw a ball straight up. The ball will land exactly from where you threw it, but if I look at you from earth's (a stationary) perspective, the ball will have moved forward too, because the plane is travelling forward.
You have to remember the explanation from the beginning of the video. If you're moving at a constant velocity everything behaves in the same manner. If you spill some coffee while you're in a plane traveling at 500 miles per hour, it spills the exact same way as if you spilled it while sitting in your kitchen, even though the floor of the plane is moving at 500 miles per hour. To everyone in the plane (unless they look outside, listen to the engines, etc.) there is no difference between the way things work while the plane is moving or sitting on the tarmac. So the light and the mirror will also behave the same way whether or not the rocket is standing still or moving.
The beauty and simplicity of the math makes the concept much more intuitive and simple. When you think about time dilation like the way you explained it, using geometry, it actually makes sense.
Brilliant video: excellent explanation and wonderful graphics! I've seen other videos of the light clock, and this is the best, IMO.
Okay, So to the person sitting in the rocket ship sees everything inside as stationary and his light clock is ticking normally. To the person on earth the light in the rocket's clock is stretched out and his own clock is ticking normally. Now to the person sitting in the rocket everything is stationary and the earth is moving by so he sees the light on the earth's clock as stretched out. Shouldn't that make time passing by equal out as the same for each person? I can understand the time difference if you only look at one perspective but there are two perspectives involved. Am I missing something?
Good thinking! That's the "Twins paradox" -- check out the first gamma video we made for a discussion.
Thanks, I'll watch the video. By the way I love your videos. Thank you so much for making them and explaining things so clearly.
actually your not, youre completely correct. both observers would see the other persons time as ticking slower than their own, and it would seem that way as long as neither of them changed speed. however, the second the person in the rocket decides to turn around and come back to earth, it breaks the symmetry of the situation, and he would start to see the person on earths clock tick faster. its a complicated thing about relativity. it doesnt work if their is accelleration involved.
ROFL at the people who are unconvinced, its been experimentally, scientifically and mathematically proven
Some people comment on this channel about the ether as if that's still relevant lol
Great video, love the emphasis on mathematics and derivation. Videos that are actually intellectual enlightening and rewarding.
I've understood special relativity decently, but never actually FULLY understood how my book derived it. Thanks a bunch, you guys are the best.
Merry Christmas Brady, and the whole team.
Still don't get it. =( I must be stupid as hell.
For instance, rocket is moving toward Earth. So time on it must be slower. But in rocket's reference frame Earth is moving with the same speed toward rocket, so time on Earth should be slower, shouldn't it?
Excuse my poor english.
Yes and no. The thing is, you are right about both of your observations but only within the correct reference frame. From the ship indeed the earth will be slower and from the earth indeed the sheep will be slower. If two objects are moving at const. vel. w.r.t. each other there is no absolute observation one can make from any of those two objects. Anything you measure from the reference frame of one of the objects will be right but only in that reference frame. There is no right answer here that applies for both earth and the spaceship regarding time dialation.
What I'm wondering, when relativity and time dilation comes up:
We're moving around the Sun at a significant speed. At least, if the Earth were to stop moving around the Sun, and stay in the same position relative to the sun, we'd probably die due to G-forces. Some of us would get thrown high into the air. So we''e going around the sun fast.
Now, suppose we send a rocket into space in the opposite direction. In fact, we send it at a speed that would make it stay in the same place where we were when we launched it.
1) Earth and rocket are at position A relative to the Sun. We launch rocket.
2) Earth is at position B relative to the Sun, and rocket is at position A.
3) Earth continues its orbit, and rocket remains on position A.
From our perspective, the rocket is moving rather fast, and as seen in this video, moving things will have a slower clock. However, from the Suns perspective, we are moving fast, and the rocket is stationary.
I used to think this weird scenario totally complicated answer, but apparently this subject answers everything rather simply, however counterinftuitive. I guess we would in fact see the rockets clock going slower than ours, while the Sun sees our clock going slower than that of the rocket? But then what would happen if the Earth came around the other side of the sun, and reunited with the rocket - would the clocks somehow be realigned again, or is one actually ahead of the other one?
We on Earth would see the rocket as being slowed down, and the people on the rocket would see Earth as having been slowed down. It is a very similar problem to the train in the tunnel gamma video. The time dilation creates a 'paradox' in which two observers see two different things.
Surely they won't be exactly "aligned", but the speed of the Earth around the sun is near 30 km/s, that is 0.01% of the speed of light. The factor gamma would be equal to 1,000000005, so the difference after 1 year, if I'm correct, would be around 0.15 seconds. But you have to think that when the rocket comes out from the Earth, it also has its speed, so somehow would need a lot of energy to "stop" anyway.
Something to be careful of is that this special relativity mathematics only works for inertial reference frames - points of view that are travelling at constant speeds relative to each other and are not accelerating. Any time something like the orbit of a planet loops around on itself you know acceleration is involved, so the more complex mathematics of general relativity tends to be needed. The twin paradox is a special case where you can apply the rules of special relativity to three reference frames by assuming the astronaut "jumps" reference frames without really accelerating, so you can get an approximate answer very simply. An orbit is more complex because the direction of travel is constantly changing.
special relativity can't handle this, but I believe that the person in the rocket will have less time, but I'm not certain.
acceleration just changes the right angle triangle the light is on. That's why space is curved if you view acceleration and gravity the same.
Amazing video ! Clear explanations and wonderful editing. Thank you.
That was amazing... especially the mind-blowing realization that light travels farther from other reference frames.
I think his shirt is inside out...
could any one explain why that light is going diagonal after it was shot? is the light being pushed along? does a perpendicular velocity apply on light?
Light consists of photons which (if the space ship is already moving) have an initial velocity in the direction in which the space ship is moving. If you think of photons as basketballs it's like throwing the basketball up in the air while being in a moving bus - the ball doesn't fall behind.
Mauno Malmivaara right... I was confused w/ the laser pointing upward...
Remember that if you're in the same reference frame as the rocket, the light IS just shooting straight up and reflecting straight back down to the sensor. It's only if you're in a different reference frame, watching the rocket go by, that the light appears to travel diagonally. It's all about the reference frame from which you're watching.
De Potter M. i was about to put the same question in the comments.
So is light on Earth as seen from the space ship also elongating?
This is the first time somebody actually convinces me about time dilation... great job.
It's very counter intuitive when you first hear about it from a physicist, but after watching this video, time dilation becomes not only intuitive but necessary
Convinces you? Lol, so you were in denial without knowing anything about it?
Well, I always believed in it, but in an almost dogmatic way, as if it was true "because the physicist says so, period".
Now I think it is true because it actually makes sense
Thanks for showing how the equation was derived. The animations were great, too!
Also if somebody travels in a rocket goes on a long journey and comes back when their relatives are old...
And the earth is moving at the same speed relative to the rocket as the rocket is to the earth.
Why doesn't that mean that the occupants of the rocket comes back old?
Impossible. The same time will elapse for both the earth and the space jockies.
When you are considering the case that the rocket stops somewhere aka the rocket changes velocity only sp. rel. will not be sufficient. You have to consider GR as well.
but from the rocket, the "stationary" clock is moving, so THEIR time should be slower.
that is what is what is confusing.
both are moving relative to each other, so why is time slowed on one?
It is understandable if one is circling the other...
by the gamma function you can see that the velocity matters, so just for the referencial who is next to the speed of light somethings happens (v²/c²)
I notice a similar effect at work all the time. We have conveyors, If you are looking right at the conveyor the speed is normal, but if you watch it out your peripheral it seems like it is moving a lot slower. Since your peripheral makes object look smaller to fit in your field of vision, the belt still travels the same distance, so it tricks your eyes into thinking the belt is moving slower, since the conveyor seems shorter.
Yes Brady!!! Seeing him take these concepts and translate them into math is so fascinating! It's also cool to see him manipulate the math as well. More like these!
Why is this not named "Gamma Revolutions"? :D
Love your channel but why did you fast forward the very bit you promised to deliver?
This was supposed to be a demonstration of the maths and that's exactly the part you rush through, by literally pushing the fast forward button, to jump to the end.
There was a clear warning at the beginning of the video that informed everyone that there would be simple basic maths ahead.
I don't understand why you flew past the guts of the thing as if it were a bad car crash that might upset the viewers.
i appreciate the matrix reference with the titles of the gamma videos
Since 'c' is simply derived, please do it for us. I'm extremely curious now
Look up jean foucault's rotating mirror experiment
he speaks too fast in my opinion, english isnt my 1st language so i have problems following him. brady is it possible to add subtitles? would be awesome
The 'transcript' or 'captions' on the video is usually pretty accurate
Why am I here? Im not smart enough to be here... Ill see yall at the comedy section of youtube.
I watched a lot of videos on this topic. I think I finally got it. Even the mathematics of it. Thank you!
Thank you for this simple explanation. I really like it. Thumbs up.
The title is misleading. Time is not slower on rockets. Having a rocket moving relative to the Earth, if you look from Earth, time is moving slower on the rocket, but if you look from the rocket, time is moving slower on Earth.
I never understood that. wouldn't that mean that there is no aging difference between people on earth and on the spaceship?
The difference comes from the fact that the rocket has to turn around at some point. The acceleration experienced during the turning is what makes the difference.
Wouldn't deacceleration when stopping make the time go faster in the rocket? There must be the same amount of deacceleration as there is acceleration so wouldn't it eventually mean no time difference?
+MiscStuff Deacceleration is still acceleration (just in the opposite direction). All frames of reference are equal so whether your speed increases or decreases is subjective. Einstein's general theory of relativity says that when your velocity changes, less time passes for you in comparison to someone moving with a constant velocity.
This video didn't just blow my mind.
I think it blew my asshole out.
Fantastic Video!
Inappropriate language, dude.
Really great animations and illustrations in this one!
thanks, i love these videos brady!
0:25 Why are uTorrent-asteroids crashing on earth ? ;)
Those are muons. They're like heavy electrons.
Those are Muons. They are sub-atomic particles that bombard the earth as cosmic radiation. They are a nice example of the effect of special relativity since they come in at a speed near the speed of light, from our reference frame their half-life time is much longer than the half-life of muons created in the laboratory.
Also Check out: Relativity Paradox - Sixty Symbols
That's the greek letter Mu, which is the symbol used for Muons (watch gamma reloaded for more info on muons).
yeah as others have said thats the greek letter mu. µ. It is used for loads of things, most notable as the symbol for the SI prefix micro. For example micro gram is µg or micro metre (micron) is µm. As others have noted it is the symbol used for muons. It is the symbol used for loads of coefficant constants in physics like the coefficient of friction.
Thanks, but that was ironic !
But thanks for not being ass***** and telling to me how I was wrong. You are awesome !
I feel like this video is missing something, but I can't quite put my finger on it...
The Jaxson Video Blog, probably because of the uncertainty principle ;)
general relativity?
i love these kinds of results :) keep it up Brady!
I love Science but I must admit most of it is beyond me. Your videos explain things so well they make things seem so easy. What a great teacher.
Damn, I'm pretty dumb.
You're not alone.
No you weren't then and you're not now. It takes courage and wisdom to determine what one doesn't know and then to endeavor to learn. Process and commitment are success; success itself is not.
You say Maxwell "derived" the speed of light. Surely the theory doesn't just give you 300,000 Km/S. He must have needed some experimental evidence to calibrate the model to get that amount.
How exactly that worked would be an interesting 60 Symbols video... just sayin'.
Yeah I second this. It could be called "c reloaded"! It may have quite a bit of maths though so maybe on numberphile?
Perfect and simple to understand. Thanks!
these gamma videos are awesome
Well clearly physics is a poor career choice for me.
To me this does not mean time speeds up or slows down...just that the tool being used to measure time is becoming less precise. I have never understood why people think that if the tool that is being used to measure something shows change then it automatically means that the item being measured has changed. Using this same logic you could say that the distance from my house to a tree increases in the winter because the wooden meterstick I always use to measure the distance shrinks when it gets cold.
Sorry I cannot read the replies right now because youtube is broken and "View all 3 replies" won't expand.
Patrick you are incorrect. Let's assume for a moment that atomic clocks are perfectly accurate. If you synchronized 3 atomic clocks to the exact same time, placed two of them on this space ship and left one on Earth, and then returned all 3 together, you would find that the two on the spaceship would agree with each other 100%, while they would differ from the atomic clock on the ground. In fact, this exact experiment has been conducted with atomic clocks flying on jets and the results are compatible with the theory of relativity.
Your wooden meterstick analogy fails because if you used two identical wooden sticks they would both change.
Patrick Guiett, if the physical mechanism that made up the light clock (the rods, springs, mirrors, etc) were all unaffected by moving through space then you would be right... it would only affect this particular tool.
But let's pause for a second and consider what those rods etc are made of. They are made of molecules and atoms which are held together by electric & magnetic force. In essence, molecules and atoms are held together by light. And that means that molecular processes (the rate of chemical reactions, the oscillations of a spring, the length of a piece of metal) are all potentially affected when moving, in the same matter as the pure light part of the light clock is.
Ie, a moving hydrogen atom (normally a proton with a spherical electron shell consisting of a moving electron) will become a flattened sphere and have its time of orbit slowed down when moving.
Of course this doesn't tell us how the Strong & Weak atomic forces and quantum behaviour are affected by moving through space, but we can assume that they work the same way (which gives us Special Relativity) and keep an eye out in experiments for any variation from that.
loved this. really easy to follow along when you explained the math instead of just showing formulas. more like this please :)
Finally I can grasp this, thanks for the really simple and intuitive explaination!
I hate what some people comment on these videos, asking such dumb uneducated questions- if you don't understand, do background reading, learn do equations don't post dumb questions that are impossible or simply incorrect
I like a lot Brady's videos and watch them daily. However, I find his aversion for math in his videos annoying. Chemistry, Math and Physics are exact sciences and mathematics are a necessary thing for understanding them.
Aversion to math? When not making sixtysymbols, I also make Numberphile --- czcams.com/users/numberphile
However, I do think if something can be explained without the "language of mathematics", that is a challenge we should tackle? It is a language many people do not speak and I don't think those people should be denied a glimpse of our universe.
In much the same way, a non-English speaker may not appreciate the beauty of Shakespeare, but we can still tell them the plots and explain WHY it is beautiful. But we don't stubbornly tell them "if you don't learn English, we will not let you know what Hamlet is about!"
Hahaha, the irony
+Sixty Symbols
English is arbitrary, like all languages. So you don't need English per say to explain anything. On the other hand, math is not arbitrary. And there are things in physics you need math to explain.
+Aeroscience Remember we are human. Language in integral to understanding many complex ideas.
+Sixty Symbols You should always make an extended video with all the maths that is needed
this was amazing, made sense to me for once, thank you for sharing this
Very Nice. Thank you for posting.
Time is not real, but man made.
There is no past or future, only now.
time... slower... ahhahahaha.... come on guys/gals... there is no such thing as time... HOW MANY TIMES DO I HAVE TO SAY THIS TO YOU? :)
you are trapped in the grand delusion... and the more you delve into it from your current perspective, the more you reinforce the illusion that time exists...
the thing you refer to as time is the resulting observations of the continuum's interaction on objects within that continuum... mechanical movement is not time... well, not really...
try not to focus so much on time, but on developing a "sight" so as to be able to "see" the continuum... (analguous to why ancient peoples could never learn how to fly planes... they didn't know about the nature of air)
the first big mistakes here is proceeding the discourse based on assumptions the the original path is straight up and down and that anything is actually stationery... after that, it's just a matter of the conversation spiraling deeper and deeper into self delusion... again, science is used to provide an a convenient explanation to validate observations, and to give answers to the wrong questions...
as hard as it is, to understand Time requires that you abandon your planes of reference about almost everything...
Why Is Timer Slower? an absurd question/statement indeed... especially when the definition of Time itself remains unsettled...
RedOcktober typical american ignorance!
I'm just starting to think the same thing... not because of your comment tho xP ... but yea... Time is just a concept. I've come up with a theory that the faster an object moves, the slower the atomic or whatever reactions etc works... so like, if you ride in a super fast rocket. All the atoms just do their thing slower and slower the faster you go. So no "time" is ever needed..... I mean, if "time" moves slower for some people just because they are moving fast... why then doesn't time move slower for everything else too? When I ride my mega fast rocket, I watch the whole world around me move mega fast. So why does time slow down for me and not everyone else? What I understand .. there is no way of knowing an absolute speed in the universe.. everything is relative to everything else.. so who is telling the universe that my mega rocket is the thing that moves über fast? It could just as well be that my rocket is stationary and everything else is moving ultra fast around me.... bleh.. whateverz.
lol
If one truly understands time and how it fits into the grand scheme, their mind has ascended to a level beyond what our 3D-based brains evolved for. It generally requires metaphors and dimensional reduction/projection to wrap your head around these things.
Even so, trying to imagine the actual hyperdimensional geometry (is there better word?) may not be possible for humans, so we've invented computers to assist.
This is just philosophical pseudo-intellectualism rather than physics.
the other videos about gamma didn't make much sense but now that he has showed how gamma works with mathematics it is a lot more clear
Thanks for such a great explanation
This was the best of the trilogy, by far. Not to say that the others weren't excellent, but this was significantly easier to follow and will help greatly in teaching others.
All this figured out by Einstein in 1905. Also in that year, he figured out the photoelectric effect, which lead to quantum theory and the theory behind solar cells (for which he won a Nobel Prize), he figured out Brownian motion, which had been troubling scientists for almost 100 years, and he figured out the mass-energy equivalence, which is the famous E=mc2. Not a bad year. As a friend of mine, who has a Ph.D. in physics, says, 'Never bet against Einstein'.
This video is awesome! Thank you very much for this content!
Excellent explanation. Thanks
I haven't enjoyed physics in long time!!
thanks for this awesome videos :)
i understand the concept behind this, it was explained very well
but the maths behind it just leaves my brain in a state of mush
the universe is a wonderful place.
8:00 A little bit of magic.
Lovely explanation, thank you
Mind = blown. You're a great teacher.
Seriously good video and very well explained. I haven't seen either of the previous videos but I still felt I got a really good understanding of an otherwise seemingly mind-boggling concept.
THANK YOU! BEEN TRYING TO GRASP THIS FOR SOME TIME
awesome animations! great job!
Mind blowing, thank you!
Thank you, Professor Mike Merrifield.
Brilliantly explained!!
Elegant explanation. Thank you.